Electric power systems, e.g. high voltage systems, such as systems for electric power transmission or distribution, often comprise capacitor units comprising one or a plurality of capacitors, e.g. medium or high voltage capacitors. These capacitor units produce sound or noise during operation, and the sound may be disturbing and have a negative effect on the surroundings. It has been suggested to enclose the capacitor unit by means of a housing or enclosure in order to attenuate (reduce) the sound from the capacitor unit. However, the capacitor unit also generates heat as a by-product during operation, which should be considered when enclosing the capacitor unit. Thus, the housing or enclosure also has to provide sufficient cooling of the capacitor unit to meet the individual unit cooling requirements at site. In order to avoid that the sound-absorptive housing interior become too hot, the housing may be provided with an inlet air opening (entrance for air) and an outlet air opening (exit for air), and a heat convection path is provided inside the housing between the inlet air opening and the outlet air opening in order to provide cooling. In order to make the housing sufficiently sound-absorptive, the inlet and outlet openings is often provided with so called sound traps, which absorb, or trap, the sound but allow the air to pass therethrough. Prior-art sound-absorptive housings with cooling are illustrated in the appended FIGS. 1-2.
Medium and/or high voltage units comprising one or a plurality of reactors or transformers may also produce sound or noise, which may have a negative effect on the surroundings.
CN 201821014U discloses a structure of a high voltage capacitor chamber comprising two layers of machine rooms and an air inlet and an air outlet for ventilation of the machine rooms. The structure is said to eliminate noise pollution.
CN 202474598U describes a sound-insulation cooling device for a transformer chamber and a reactor chamber.